This invention relates to a method and apparatus to store machine tool end effectors, and more particularly to a method and apparatus to store one or more end effectors in a storage station with multiple storage cells.
Within the manufacturing industry, many manufacturing processes utilize computer or numerically controlled machine tools. These tools, which often utilize robotic arms, are beneficial in terms of improving product quality, increasing time efficiency, reducing labor requirements, and alleviating unnecessary tooling costs. The benefits occur, in part, because many versatile robotic manufacturing tools are capable of completing more than one manufacturing task, such as drilling and routing, while the work piece remains in one position within the manufacturing station. The extent or type of manufacturing process available partially depend upon the sophistication of the tool and robotic arm. A fairly sophisticated NC machine and associated robot arm may be programmed to pick up one end effector, complete a manufacturing task, replace the end effector, and pick up a different end effector to complete a different task.
To accomplish these multiple manufacturing steps, a plurality of end effectors must be positioned at an exact location and orientation in space that correspond with information programmed in the NC machine tool. Each end effector must also be stored within the robot arm's longitudinal and radial reach.
Manufacturing industry continuously strives to reach machining process goals that include reducing manufacturing time, increasing efficiency, avoiding wasted machine movement, and minimizing the manufacturing tool's floor space requirement. As such, a highly desirable end effector storage station is one that locates and stores a plurality of end effectors in a manner that facilitates efficient and accurate connections with the robot arm.
In the past, multiple end effectors have been stored in large end effector racks. Typically the end effectors sit such that the end effectors' longitudinal axis is vertically oriented with the end effectors connecting plate faces up. Each vertically aligned end effector must have enough surrounding space that allows the robotic arm access to engage the end effector. Once engaged, the robot must pick up the end effector vertically out of a vertical holder, and then withdraw and/or rotate the end effector to the programmed orientation.
Past end effector racks also usually stored end effectors in vertically oriented holders. These holders utilized gravity to properly hold the end effector in the rack, and springs to absorb impact unwittingly inflicted by the robot arm. Such impact usually occurs while engaging, disengaging, replacing, or removing the end effector.
Vertically orienting end effector has several disadvantages. The robot arm must move along a greater range of motion. The space around each end effector must be greater to allow the robotic arm adequate access to the end effectors and to ensure against inadvertent damage while picking up or replacing the end effector into the holding rack. Greater space requirements generally result in the need for more manufacturing floor space to accommodate all the desired manufacturing processes. In addition, excess robotic arm movement and larger end effector holding racks generally translates into using a larger or more bulky manufacturing tool to satisfy design requirements.